EEG as a Predictive Tool for Seizures and Survival Outcomes Related to CAR T-cell Therapy
Guido Chiriboga1, Thomas Pecha1, Andy Shar2, Oluwatoni Betiku3, Anteneh Feyissa1, Cornelia Drees4, Wendy Sherman1, Hong Qin1, Jeffrey Britton5, Alfredo Quinones-Hinojosa1, William Tatum1, Brin Freund1
1Mayo Clinic, 2Virginia Commonwealth University, 3University of Florida, 4Mayo Clinic Arizona, 5Mayo Graduate School of Medicine
Objective:
To analyze EEG patterns and outcomes in patients undergoing CAR T-cell therapy for hematologic malignancies.
Background:
Chimeric antigen receptor T-cell (CAR T-cell) therapy poses a risk of immune effector cell-associated neurotoxicity syndrome (ICANS), which may include encephalopathy and seizures and can lead to worsened outcomes. EEG is often required, but its utility in prognosis regarding seizure risk and outcomes following treatment is not well described.
Design/Methods:
This is a retrospective study including patients receiving CAR T-cell therapy across all 3 Mayo sites between October 2019 and July 2024 to assess EEG features and associated outcomes and seizure risk.
Results:
A total of 206 patients were included (median follow-up 14 months, IQR 5-20), 104 underwent baseline EEG before treatment and 82 underwent EEG (37 continuous EEG) in the acute phase of ICANS. Baseline EEG demonstrated epileptiform discharges (n=1/104), and mild (n=16/104) or moderate (n=4/104) encephalopathy with concomitant regional slowing (n=1/104). EEG during acute phase of ICANS demonstrated encephalopathy (78/82, 95.1%), sporadic epileptiform discharges (6/82, 7.3%), and rhythmic and periodic patterns (RPPs) manifest by generalized periodic discharges (GPDs) with (n=19/82) and without (n=6/82) triphasic morphology, lateralized periodic discharges (n=2/82), and lateralized (n=5/82), generalized (n=5/82), or frontal intermittent (n=5/82) rhythmic delta activity. Acute symptomatic seizures (ASyS) occurred in 9 patients, 2 being subclinical requiring EEG for diagnosis. Characteristics of baseline EEG and EEG during ICANS were not associated with seizures. Encephalopathy on baseline EEG was predictive of a higher likelihood of death at last follow up (p=0.029) and shorter survival (p=0.002) following CAR T-cell therapy.
Conclusions:
EEG performed during ICANS from CAR T-cell therapy demonstrates low rates of seizures, with the most frequent finding being encephalopathy. RPPs are also seen, with GPDs with triphasic morphology being most common. The presence of encephalopathy on baseline EEG predicts worse outcome following CAR T-cell therapy.
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